TEGULALITHUS A IEV GEIUS OF .EARLY CRETACEOUS CALCAREOUS IIABBOFOSSILS

Jason A. Crux
Stratigraphy Branch, BP Research Centre
Chertsey Road, Sunbury-on-Thames
Middlesex TW16 7LN, UK
Two species <Lithastrinus septentrionalis Stradner 1963, Lithastrinus
tessellatus Stradner 1968) previously assigned to the genus Lithastrinus
Stradner 1962, do not conform to the generic diagnosis. A new genus,
Tegulalithus, is erected here to include these species.

Tegulali thus gen. nov.
Type species: Lithastrinus septentrionalis Stradner 1963
Derivation of name: <Latin) Tegula - a roof tile
Diagnosis: Circular or subcircular coccoliths consisting of proximal anddistal plates composed of numerous small rhombohedral crystals which
overlap one another like roof tiles. These plates are perforated by asingle hole and may be joined to one another by 16 to 30 large wall
forming elements.
Comments: The holotype of Lithastrinus septentrionalis is a line drawing
interpreted from the light microscope. The structure shown does notmatch that observed in the scanning electron microscope for this species<Pl. 1, Figs. 1, 2). However, the holotype is from the Late Hauterivianof Germany as are the specimens shown here and. it resembles the forms
illustrated by the light micrographs in Pl. 1, Figs. 3-5
Reinhardt <1970) also assigned specimens similar to those observed in
the present study to the species L. septentrionalis <Text-Fig. 74, Pl.
5, Figs. 6,7; Pl. 6, Fig. 1). However, his concept of the species
included L. tessellatus, which is considered to be a separate species in
the present study.

Tegulalithus septentrionalis <Stradner 1963> nov. comb.
Pl.1, Figs.1-5.
1963

Lithastrinus septentrionalis Stradner, p. 177, Pl.2,Fig.7a-b.

)984

Eprolithus septentrionalis <Stradner> Perch-Nielsen, p. 43.

Comments: Tegulalithus septentrionalis does not conform to the genericdescription of Eprolithus Stover 1966. The possession of the distal andproximal plates composed of rhombohedral crystals is unique to thespecies T. septentrionalis and T. tessellatus.

INA Newsletter vol.B- 1986
88

Tegulali thus tessellatus <Stradner 1968> · nov. comb.
1968

Lithastrinus tessellatus Stradner in Stradner, Adamikerand Maresch, p.43, Pls. 43 and 44, Text Figs. 7/1 and 7/2.

Comments: T. septentrionalis can be differentiated fromT. tessellatus by a greater number of rhombohedra! crystals in theproximal and distal plates of the latter. No illustrated specimens ofT. tessellatus show the 16-30 large wall forming elements observed in T.
septentrionalis, the presence or absence of these elements may be
another diagnostic feature.
T. septentrionalis is stratigraphically restricted to the Late
Hauterivian, while r. tessellatus occurs in the Aptian to Albian.
REFERENCES
Mutterlose, J. 1984 Die Unterkreide-Aufschlusse <Valangin-Alb> im Raum
Hannover-Braunschweig. Hitt. geol. Inst. Univ. Hannover, 24, 1-61.
Perch-Nielsen, K. 1984 Validation of new combinations. INA Newsletter,6, (1), 42-46.
Reinhardt, P. 1970 Synopsis der Gattungen und Arten dermesozoischen Coccolithen und anderer kalkiger Nannofossilien.
Part II . Freiberger Forschungsh., C265, 41- 111.
Stradner, H. 1963 New contributions to Mesozoic stratigraphy bymeans of nannofossils. Proc. 6th Vorld Petrol. congr. Sect. 1
paper 4, 167-182.
Stradner,H. ,Adamiker,D.and Maresch,O. 1968 Electron microscopestudies on Albian calcareous nannoplankton from the Delft 2and Leidschendam 1 Deepwells, Holland. Verh. Kon. Ned. Akad.
Vetensch., Afd. Natuurk., 24 <4>, 1-107.

Plate 1Figs. 1-5 Tegulalithus septentrionalis <Stradner 1963) nov. comb.
1. Plan view, 2. Side view, X 10.000, Otto Gott, Bed 50, gottschei
Zone.
3. Plan view, x-nicols, 4. Plan view, bright field, X 2.800,Moorberg, Bed 67, staffi Zone.
5. Side view, bright field, X 2.800, Moorberg, Bed 67, staffi
Zone.
Bed numbers after Mutterlose <1984).

INA Newsletter val.B- 198689

Plate 1